What could be the cause

Hailee • Married June 2014. TTC since Aug. Lost baby #1 at 4 weeks on New Years of 2015.
Alright. These two pics are my temp since ovulation. I was suppose to start Feb 1st and have not. I took a test Jan 26th and got a neg. my temp keeps changing and yes I missed a couple days. I thought I was going to pee the bed as soon as I woke up thos days so I didn't get the chance to take my temp. Anyone know what could cause me being late. Besides pregancy. I don't wanna get my hopes up had a MC New Years.